He replies, “UR [You are] funny. We are on the same server.” His reply goes to Mills as well as Abedin, indicating that both of them are aware of the existence of Clinton’s private server.

Cooper’s email domain will be redacted when this email is released in 2016, but his comment indicates his email is on the clintonemail.com domain, the same as Clinton’s. (Abedin has an email account on that domain too, but she sends this email from her State Department state.gov account.) (US Department of State, 6/20/2016)

Cooper is not a government employee and apparently has no security clearance, but other reports indicate he helps Bryan Pagliano manage Clinton’s server.

Huma Abedin, Clinton’s deputy chief of staff, writes Clinton that after another aide named Judith wrote Clinton an email, “It bounced back. She called the email help desk at state (I guess assuming u had state email) and told them that. They had no idea it was YOU, just some random address so they emailed.” (US Department of State, 8/31/2015)